Document Type

Article

Publication Date

1-2017

Keywords

tephra fallout, inversion, uncertainty analysis, data worth, volcanology

Digital Object Identifier (DOI)

https://doi.org/10.1002/2016JB013682

Abstract

An efficient and effective inversion and uncertainty quantification approach is proposed for estimating eruption parameters given a data set collected from a tephra deposit. The approach is model independent and here is applied using Tephra2, a code that simulates advective and dispersive tephra transport and deposition. The Levenburg‐Marquardt algorithm is combined with formal Tikhonov and subspace regularization to invert eruption parameters; a linear equation for conditional uncertainty propagation is used to estimate posterior parameter uncertainty. Both the inversion and uncertainty analysis support simultaneous analysis of the full eruption and wind field parameterization. The combined inversion/uncertainty quantification approach is applied to the 1992 eruption of Cerro Negro and the 2011 Kirishima‐Shinmoedake eruption. While eruption mass uncertainty is reduced by inversion against tephra isomass data, considerable uncertainty remains for many eruption and wind field parameters, such as plume height. Supplementing the inversion data set with tephra granulometry data is shown to further reduce the uncertainty of most eruption and wind field parameters. The eruption mass of the 2011 Kirishima‐Shinmoedake eruption is 0.82 × 1010 kg to 2.6 × 1010 kg, with 95% confidence; total eruption mass for the 1992 Cerro Negro eruption is 4.2 × 1010 kg to 7.3 × 1010 kg, with 95% confidence. These results indicate that eruption classification and characterization of eruption parameters can be significantly improved through this uncertainty quantification approach.

Was this content written or created while at USF?

Yes

Citation / Publisher Attribution

Journal of Geophysical Research: Solid Earth, v. 122, issue 1, p. 281-294

©2017. American Geophysical Union. All Rights Reserved.

TextS1.pdf (167 kB)
Summary of Tephra2 formulation

Data Set S1.csv (16 kB)
Tephra thickness and grainsize data used for analysis of the 2011 Kirishima eruption

Data Set S2.csv (9 kB)
Tephra thickness and grainsize data used for analysis of the 1992 Cerro Negro eruption

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